Araneus
, , , , , , , , | abbreviation = Arn | genitive = Arani | pronounce = Name: /'ār•ān•ē•(y)is/ Genitive: /'ār•ān•ī/ | symbolism = the | mRA = | mdec= | ndec = | sdec = | wRA = | eRA = | quadrant = NQ1 | crossedby = Summer meridian | bordering = Avis (N) Hippocampus (SW) Felis (E) Malus (SE) Selachimorphus (S) Testudo (NW) | segments = 48 | area = 4339.308 sq. deg. (4 ) | proportion = 105.188‰ | average = 482.145 sq. deg. (6 ) | namedstars = 61 | figurestars = 11 | nakedeyestars = 504 | bfstars = 546 | brightstars = 32 | brighteststar = (−1.46 }}) | nearbystars = 30 | neareststar = (2.64 , 8.60 ) | messierobjects = 12 | fullrange = 56°N–33°S | partialrange = 90°N–56°N 33°S–90°S | date = December 6 | astrosign = 3/21–6/21 | solarsign = 4/19–7/20 }} Araneus is a caelregio located in the first quadrant of the at its midpoint, but it extends into the southern hemisphere and into the second quadrant. Araneus is divided into nine s (listed in the infobox). Araneus contains one of the most magnificent constellations, . In addition, Araneus also contains the sky's brightest star as well as numerous other bright stars, competing with Simianus for the brightest caelregio. Six of the bright stars make up the , which is the most complex and recognizable seasonal . This caelregio contains numerous examples of deep sky objects including the (the most famous open cluster) and two most famous nebulae: the and the . Combining all of these features would make Araneus the most conspicuous caelregio. Symbolism Araneus is named after the Latin word for , even though there are no spider-related constellations. It can be imagined that spiders were eaten by ram (Aries), dogs (Canis Major & Canis Minor), hare (Lepus), and bull (Taurus). For Gemini the Twins, spider crawl from one member to another via connected arms while biting. Notable stars Bright stars Araneus contains the sky's brightest star Sirius at a of −1.46, which is an star located in the constellation , and is also the Araneus' nearest star (sixth nearest star system overall) at a of 8.60 s (2.64 s). Sirius is one of the stars that make up the , the other two are Procyon and Betelgeuse, both will mention below, which means that all the stars that make up the Winter Triangle are located in this caelregio. There is also the Winter Hexagon with the component stars Sirius, Procyon, Pollux/Castor, Capella, Aldebaran, and Rigel, all of these will mention below. Like the Winter Triangle, every component stars that make up the Winter Hexagon are located in Araneus. is a located in Orion. It is expected to go supernova within a million years. With the magnitude of 0.58, it is the second brightest star in Orion and eighth brightest overall. The star radiates 140,000 times quicker than our Sun and it is 498 light-years from Earth. Betelgeuse is the first star other than our Sun to have its measured in 1920, the estimate ranges from 43 to 58 s. is a also located in Orion. With the magnitude of 0.12, it is the brightest star in Orion and sixth brightest overall. Rigel is 117,000 times more luminous than our Sun and it is 863 light-years away. Also in Orion, is a B-type giant. is an located in . Its diameter is 44 times that of the Sun and it is 425 times more luminous than our Sun. Aldebaran is one of the four brightest stars within 5° of the , the others are in Noctua, in Felis, and in Simianus. and are a pair of brightest stars located in . Castor is a white star while Pollux is an orange star that was once a white star like Castor. Castor is 51 light-years away while Pollux is 34. is the brightest star in and third brightest star in the northern sky after and . The brightest member of the four-star system is a . is the brightest star in and the seventh brightest in the sky at 0.34 . It is an F5IV-V star with seven times the energy output of the Sun. Nearby stars The only notable nearby star in Araneus other than Sirius is , which was the first star known to be orbited by a . Gliese 229 is a 18.77 light-years (5.75 parsecs) away in the constellation . Variable stars The can be found located in the Hind's Variable Nebula to be mentioned below. T Tauri varies unpredictably in from 9.3 to 14. Like all T Tauri stars, T Tauri is very young, at only a million years old. The Sun was probably a T Tauri star within a few million years of Sun's birth. Another notable T Tauri star is . The magnitude varies between 10 and 12. This "star" is not more than a very bright concentration of gases within the Hubble's Variable Nebula to be mentioned below. Some star atlases and sky catalogue do not list R Mon as a star, but a nebula. The can be found. This type is the high temperature version of CVns}}. This star varies by about 0.1 magnitude at around one day and has a strong and an uneven surface distributions of . is an system. Every 27 years, the magnitude drops from 2.92 to 3.83 which lasts 640–730 days. contains an eclipsing binary between a and a K-type star. There is the star . It is a that may have ejected from the Trapezium Cluster in the Orion Nebula two million years ago. AE Aur is currently surrounded by the Flaming Star Nebula to be mentioned below. is 1800–2100 times the diameter of the Sun, making it the biggest star known. This red star is also a with a period around 2000 days or between five to six years. Betelgeuse is a varying between magnitudes 0.2 and 1.2 as the star pulsates. Betelgeuse has the greatest magnitude variation of any first magnitude stars. is a with extreme changes in brightness and spectral type. Multiple stars Sirius contains the stellar companion Sirius B, which was the first discovered in 1915. The two white stars orbit around the at a distance of 20 (about the Sun– distance) and takes 49.9 years to revolve. To resolve two individual stars of Sirius, at least a 12-inch would be needed as the is between 3" to 11". In Gemini, the sextuple Castor can be found. It contains two and two . This system contains three A-type stars and three M-type stars. In Auriga, the brightest star Capella is a comprising of four stars with two s –– two yellow giants and two red dwarfs. In Canis Minor, Procyon is a comprising of an F-type main sequence star and a . Since the angular separation is only 1.232", a large telescope would be needed to resolve two stars of Procyon. is a comprising of a binary pair and a binary orbiter. The binary period is greater than 5000 years and both A-type main sequence stars are separated by 7.7 s, which is separable in small telescopes. The third member is 221 arcseconds distant, 29 times further separated from the pair than the members of the pair, which can be separated using just the . discovered one of the first systems in 1664. Planetary systems There are nearly a hundred s identified around approximately 70 stars in Araneus. Two notable examples are Pollux (P15 Arn), which contains a giant planet (P181) on a 590-day orbit, and (P47 Arn) in Aries, which contains a giant planet (P520) on a 381-day orbit. A more notable example is (P30 Arn) in Monoceros, which contains two confirmed super-Earths (respectively (Icarus, P311) and (Daedalus, P338)) and one unconfirmed midplanet ( (Tutelina, P434). All three would orbit within 0.1 AU. Icarus was found by , while Daedalus and Tutelina were found by from . Both Icarus and Daedalus are so-called s while Tutelina is blue and cloudless. A strange example is (P23 Arn), located in Auriga, which has a dying planet (Vulcan, P262) because the star is devouring the planet. Vulcan orbits at a distance of only the Earth–Sun distance and takes 1.09 days or over 26 hours to orbit. Vulcan has mass 1.39 }} and radius 1.83 }}, yielding a mean density that of water or that of . Scientists expect that Vulcan will be devoured in 10 million years. Another notable exoplanet is 30 Arietis Bb (Ino, P374), which orbits the star (P36 Arn, component of the 30 Arietis system) at an of 0.98 AU and 29% eccentric. This planet has mass 12.95 M and 10% larger than Jupiter in diameter, corresponding to a mean density 13.2 g/cm , 10 times denser than . In Taurus, (P1 Arn) has three s with changing dynamics caused by gravity between the planets. Notable deep sky objects Araneus contains the famous s ( 45), which contains seven bright blue stars, called the "Seven Sisters," and ( 25, 41), both located in Taurus. Also located in Taurus, the (M1, NGC 1952) is a of a after the progenitor star exploded in 1054, which was observed by Chinese astronomers. Another supernova remnant, in Gemini, is the ( 443). Located in Monoceros, we find the ( 2264), which contains the (NGC 2264), which is an . This nebula is and . In Gemini, we find the typical . In Auriga, we find the open cluster along with two other open clusters: and . In Canis Major, we find the open cluster which contains several s. The famous (M42, NGC 1976) is a located in Orion. This nebula contains the at its heart, which is a tight open cluster of young stars formed out of the parent nebula. This constellation also contains the ( 33), which is a famous dark nebula where stars are forming, the (NGC 2024), which is an , and the (NGC 2174), which is a . In Auriga, there is the (IC 405, C31), which is a /emission nebula surrounding the irregular variable star AE Aurigae mentioned above. The (NGC 2346) is a planetary nebula located near the equator in Monoceros. In Gemini, the (NGC 2392, C39), also known as the Clownface Nebula, can be found using a small telescope, which is a planetary nebula. Another planetary nebula in Gemini is the ( 21, -274). In Canis Major, (NGC 2359), which is an , can be seen. The (NGC 2237, C49), which is one of the most massive stellar nurseries at around 10,000 es, can be found in Monoceros using the . The planetary nebula ( 44179) can be found in Monoceros. Also in this constellation, there is the (IC 2177), which is an emission nebula. Another emission nebula (Sh2-276) and reflection nebula are found in Orion. There are two examples of planetary nebulae in Taurus: the (B207), which is a dark nebula, and (NGC 1514), which is a planetary nebula. There is the (Sh2-308) in Canis Major, which is also a planetary nebula. Located in Taurus, (NGC 1555) is a illuminated by the prototype variable star T Tauri. Another notable variable nebula, located in Monoceros, is (NGC 2261, C46) illuminated by the variable star R Monocerotis. In Canis Major, we observe that two are currently in the first stage of . In about a billion years, the two spiral galaxies will become one . Also in this constellation, there is the discovered in 2003, which is the nearest irregular galaxy|irregular}} galaxy to the Milky Way at just 25,000 light-years distant. This galaxy contains about one billion stars, many of which are red giants. Gallery Notable meteor showers Every year on December 13–14, the (also called December Aranids) peak, caused by the . This is intensifying every year and recently seen 120–160 meteors per hour. Every year on October 20–24, the (also called October Aranids) peak, caused by the famous . It can often produce 20–70 meteors per hour. Every year on June 7, the (also called June Aranids) peak, caused by the asteroid . It can produce 54 meteors per hour. Every year on November 3, the (also called November Aranids) peak, caused by the . It can produce about 7 meteors per hour. Because of their occurrence from late October till early November, they are often called Halloween . Visibility In the northern hemisphere, Araneus can be visible during the fall and winter months. A significant portion of this caelregio can be observed from around the world because Araneus is an equatorial caelregio, but a larger portion is more prominent in the northern hemisphere because the area of Araneus north of the equator is greater than the area south of the equator. The most prominent constellation in this caelregio is Orion, which contains the Orion's belt of three stars and the sword. Araneus is one of the brightest and most recognizable caelregios with all but one constellation containing at least two bright stars (m<3.00). Zodiac The appears to cross Araneus from April 19 till July 20: it crosses the constellations Aries (April 19 till May 13), Taurus (May 14 till June 19), and then Gemini (June 20 till July 20). This al caelregio is located between Hippocampus to the west and Felis to the east. Araneus was formerly in the from March 21 till June 21. Category:Articles Category:Caelregios